I always thought that cheating on you was your final breaking point.
I would consider an old GF coming round to see you cheating.
(there was a time when I thought it was OK for him and I needed to trust him.
Now, 18 years later, I learned that they were "together" while I thought he was telling her all about me and why it was over with her.)
I read your post and I don't see what sounds rewarding or FUN in your life with him?
Dating is supposed to be fun.
eta: I read your reply to Suki. "Is he really doing the best he can? Can't he do more?" The answer is probably "Yes. NO. and at any rate, that is HIS business. Your business is deciding if you want him as he is TODAY."